This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 16 |
| 3 | 79 |
| 4 | 336 |
| 5 | 1144 |
| 6 | 4351 |
| 7 | 17224 |
| 8 | 67936 |
| 9 | 267919 |
| 10 | 1063216 |
| 11 | 4233904 |
| 12 | 16882191 |
| 13 | 67380304 |
| 14 | 269142736 |
| 15 | 1075602319 |
| 16 | 4299846976 |
| 17 | 17192621224 |
| 18 | 68752838911 |
| 19 | 274965310744 |
| 20 | 1099740514416 |
| 21 | 4398645585679 |
| 22 | 17593754283616 |
| 23 | 70372850295904 |
| 24 | 281485727082511 |
| 25 | 1125928050595744 |